Process for polymerization of aqueous acrylate paint

Abstract

A polymerizing method for water paint, especially for raising property of acr water paint. The process is that, dripping monomer and initiator into emulsifier aqueous solution having part of initiator, hard monomer, pH value buffer to react, dripping soft monomer continuing heat insulation reaction, adding siloxane crosslinking agent, keeping pH value in definite range to forming protection to siloxane, so making organic siloxane presence stable in emulsion using water as medium and mainly distributed on latex surface in forming film to raise film forming crosslinking degree. Said invention provides a simple process, fine film property and performance improved method.

Description

Technical field: [0001] The invention relates to a polymerization method for water-based paint, in particular to a polymerization method for improving the performance of acrylate water-based paint. Background technique: [0002] Waterborne acrylate copolymer emulsion has excellent weather resistance, acid and alkali resistance, stain resistance, environmental friendliness and other properties, and has become an important coating variety. However, pure acrylic and styrene-acrylic coatings have defects such as high film-forming temperature, low mechanical strength of the coating film, and poor anti-adhesive properties. They can only be modified by introducing functional monomers, or by means of core-shell emulsion polymerization and soap-free polymerization. It is unable to meet the increasingly high application requirements. Therefore, people have conducted a lot of research on emulsions capable of forming films at room temperature, such as: US 4772680 obtains room temperatu...

AI Technical Summary

Problems solved by technology

Although common unsaturated organosiloxanes such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris(β-methoxyethoxysilane) can be used in solution polymerization to improve solution performance, but Since siloxane is easily hydrolyzed, a large amount of coagulation is produced, and the polymerization reaction cannot be carried out in the aqueous phase. Therefore, the application of direct polymerization of organosiloxanes containing unsaturated groups and other organosilicon monomers to improve emulsion properties is still very limited. few

Although JP51-146525 and JP54-3512 are directly polymerized with organosiloxanes containing unsaturated groups and other organosilicon monomers, the stability of the emulsion is poor, and separation and coagulation occur

CN1217360A, CN1217360A uses hydroxyl polysiloxane to protect organosiloxane, the method first synthesizes hydroxyl polysiloxane, then adds it to the polymerization system, and carries out grafting reaction between hydroxyl siloxane and organosiloxane to protect organosilicon The oxane is not hydrolyzed, and the grafted siloxane is used as a crosslinking agent to improve the performance of the emulsion, and the process is complicated

In addition, in the current emulsion polymerization process, the cross-linking agent is often added when the monomer is dropped or pre-emulsified, and part of the cross-linking agent is wrapped inside the latex particles, which does not contribute to the inter-particle cross-linking; this reduces the cross-linking agent. The probability of distribution on the surface of latex particles not only requires a large amount of crosslinking agent, but also reduces the degree of crosslinking of the film when the particles are piled up to form a film.